By "Turbo Tax dropped my MT state return", I assume you mean "TurboTax decreased my MT state refund". Please note that a "return" is the set of pages you send to the IRS or a state department of revenue in the form of a tax return document, while "refund" refers only to the money that you may or may not receive back from the taxing authority. While these terms are widely misused by non tax professionals even on these forums, it would help us a lot if you would bear this in mind when posting questions.
Wyoming, as I am sure you know, does not levy an income tax. Montana does, but the size of your refund will vary based on a variety of factors in your situation, none of which we know yet.
At the very least, please confirm the following:
1. Did you actually mean that the Montana refund decreased when you added Wyoming?
2. Did you have any income in Montana?
3. Did you indicate that you were a resident, part-year resident, or non-resident of Montana?
4. The Montana tax return starts this way: "Your income on your Montana tax return begins with your Federal Adjusted Gross Income. ". This means that when you add income from another state, since it will increase your Federal Adjusted Gross Income, the tax in Montana will likely increase (and therefore the refund would normally decrease).
5. However, there are mechanisms in most states to prevent multi-state double taxation, whether it is a credit for taxes paid in another state or allocation of percentage of income to a state or whatever.
So for use to help you, we need to know things like your residency in both states, your income in both states, and what your research shows is not "right". Otherwise, we would just be guessing...
